infinitesolid2 Posted October 29, 2009 Posted October 29, 2009 (edited) We have the sun, then planets rotating around the sun and moons rotating around the planets. If there is no gravity in space(evidant by space junk floating around), how do the planets stay in orbit? 1: Gravity could be a exp sine preshure wave where each planet sits on a peak possibly shifed slitly by its weight. What do you think? Edited October 29, 2009 by infinitesolid2
insane_alien Posted October 29, 2009 Posted October 29, 2009 there is plenty of gravity in space, space junk is in free fall. read up on your orbital mechanics. also, we have satellites orbiting the sun between planetsqite comfortably pretty much lflying in the face of your wave theory. the phenomenon of gravity waves(not this) may exist but is nothing at all like what you obviously think.
infinitesolid2 Posted October 29, 2009 Author Posted October 29, 2009 (edited) there is plenty of gravity in space, space junk is in free fall. Would'nt the russian spacestation crashed to earth by now? and ive never heard of astronaughts beigh pulled to the sun at it's gravity speed. The spacestation is outside of earths gravity yet it follows us orbiting the sun. There must be more to this. __________________________ "Infinite Space" - Nothing stoping you travel forward forever! "Finite Universe" Space surrounds matter. The bounds of space is defined by a piece of matter. "Dark Energy" Holding everything together. Edited October 29, 2009 by infinitesolid2
insane_alien Posted October 29, 2009 Posted October 29, 2009 the russian space station has crashed to earth but it was a controlled de-orbit if they hadn't specifically made it crash then it would still be up there. and why would astronauts be pulled into the sun? the space station and satellites and astronauts are constantly falling towards the center of the earth but they also have a horizontal component to their vellocity which means they always miss the earth. they don't just magically hover up there, they need to move quite fast or else they'd fall into the earth(although it they move too fast they'll be on an escap trajectory which means they won't be coming back near earth. objects in a gravitational field do not get pulled along at any specific velocity, but they do experience a force which gives them an acceleration. in the case of an orbit this acceleration is towards the center of the planet, if you have sufficient velocity then this acceleration will result in you moving in a circle around the planet.
infinitesolid2 Posted October 29, 2009 Author Posted October 29, 2009 and why would astronauts be pulled into the sun? Because of it's gravity, if there is any that far out? If theres no gravity then what is going on? __________________________ "Infinite Space" - Nothing stoping you travel forward forever! "Finite Universe" Space surrounds matter. The bounds of space is defined by a piece of matter. "Dark Energy" Holding everything together.
swansont Posted October 29, 2009 Posted October 29, 2009 Would'nt the russian spacestation crashed to earth by now? and ive never heard of astronaughts beigh pulled to the sun at it's gravity speed. The spacestation is outside of earths gravity yet it follows us orbiting the sun. There must be more to this. Gravity falls off as 1/r^2. Nothing is outside of the pull of gravity; all that you can say is at some point r is large enough that the force becomes negligibly small.
infinitesolid2 Posted October 29, 2009 Author Posted October 29, 2009 Gravity falls off as 1/r^2. Nothing is outside of the pull of gravity; all that you can say is at some point r is large enough that the force becomes negligibly small. I understand the linearity of gravity, but take jupiter, its very heavy, probably more heavy than the gravity its receiving from the sun.
insane_alien Posted October 29, 2009 Posted October 29, 2009 thats the thing though, gravity isn't linear. it follows an inverse square relationship with distance. if there is a mass then there is a gravitational field to infinity meters away from the object.
infinitesolid2 Posted October 29, 2009 Author Posted October 29, 2009 thats the thing though, gravity isn't linear. it follows an inverse square relationship with distance. if there is a mass then there is a gravitational field to infinity meters away from the object. If at distance infinity gravity is at zero than what is it at infinity+1?
insane_alien Posted October 29, 2009 Posted October 29, 2009 infinity+1 = infinity. btw, i did the math on the suns gravitational field strength at jupiters orbit. it comes out to be 2.353x10^-4 m/s^2 this means jupiter is accelerating towards the sun at that rate constantly(and has been since it was created) this is also the acceleration necessary to have it go round the sun in a circle with the same linear velocity as jupiter has.
Sisyphus Posted October 29, 2009 Posted October 29, 2009 Astronauts are falling towards the sun, as is the Earth. It's just not getting closer, because it is moving fast enough sideways that the direction it is being accelerated is constantly changing. If you throw a ball horizontally, it follows a curved path to the ground, right? Even though through the whole path it is being accelerated down by gravity. Yet the Earth is curved, and "down" at the point where you throw it is in a slightly different direction as "down" where it lands. Throw the ball hard enough, and the rate at which the path curves will be the same as the curvature of the Earth, and it will just circle endlessly without ever hitting the ground, even though it is "falling" the whole time. That is what an orbit is. If it wasn't falling (constantly being accelerated by gravity towards the Earth's center), it would fly off in a straight line, not go in a circle.
infinitesolid2 Posted October 29, 2009 Author Posted October 29, 2009 If you can't define the point of infinity then the math does not hold true. It's a guess?
insane_alien Posted October 29, 2009 Posted October 29, 2009 the point of infinity is defined. although it is an imaginary point to be sure as there is no number where you add one and get infinity. it is a point that cannot be reached. but the math does work right to the edge of the universe and beyond. it also matches up well with reality. it can be used to predict the motion of planets and even stars and galaxies(although the refinement that is General Relativity is preffered as it is more accurate)
timo Posted October 29, 2009 Posted October 29, 2009 If there is a mass then there is a gravitational field to infinity meters away from the object. You should really not phrase it like this unless you can show me a point in space that is infinity meters away from a source of your choice. If there is no such point then statement about the gravitational field at a non-existing point is somewhat pointless (pun intended).
infinitesolid2 Posted October 29, 2009 Author Posted October 29, 2009 the point of infinity is defined. although it is an imaginary point to be sure as there is no number where you add one and get infinity. it is a point that cannot be reached. but the math does work right to the edge of the universe and beyond. it also matches up well with reality. it can be used to predict the motion of planets and even stars and galaxies(although the refinement that is General Relativity is preffered as it is more accurate) The math seems made up to me. Who made it up?
Klaynos Posted October 29, 2009 Posted October 29, 2009 The math seems made up to me. Who made it up? This is a discussion of newtonian mechanics... The derivations are quite pleasant and the experimental evidence phenomenal...
infinitesolid2 Posted October 29, 2009 Author Posted October 29, 2009 (edited) I believe to replace infinity with some number?!! Merged post follows: Consecutive posts mergedis there an easy quick read on newtonian mechanics? please keep it simple think i need to learn math, its all triangles and arrows. __________________________ "Infinite Space" - Nothing stoping you travel forward forever! "Finite Universe" Space surrounds matter. The bounds of space is defined by a piece of matter. "Dark Energy" Holding everything together. Merged post follows: Consecutive posts mergedSend out a ship at fast speed towards a marker in space, acording to special relativity time for the ship slows down. You can see the marker, it's in general relativity time. can you still see the ship if it's in a different time? Is there now 2 ships one in general time and one in special time? Can special relativity be possible? Is the ship in the past or the future? Is this time travel? I hardly think so. Edited October 29, 2009 by infinitesolid2 Consecutive posts merged.
Bignose Posted October 29, 2009 Posted October 29, 2009 If you can't define the point of infinity then the math does not hold true. It's a guess? Anyone else see the irony in a user who gave themselves the name "infinitesolid2" have a problem with the concept of infinity? I think it's rather humorous.... is there an easy quick read on newtonian mechanics? please keep it simple "simple" is a relative term. Today' date=' to me, the math is relatively simple, but that is because I am now well versed in advanced math. Had you presented me with the math before I knew calculus, then I would not have called it so simple. If you don't know calculus, then it is not very likely that what you will be presented with will be called "simple". So, the question come back to you: how simple is "simple"? Because any good university calculus-based physics text is going to cover Newtonian mechanics thoroughly. If you are looking for a specific recommendation, Serway's [i']Physics for Scientists and Engineers[/i].
Klaynos Posted October 29, 2009 Posted October 29, 2009 I believe to replace infinity with some number?!! You can take the limit of infinity... In this case IIRC it is a limit in an integral... is there an easy quick read on newtonian mechanics? please keep it simple think i need to learn math, its all triangles and arrows. Without a good understanding of maths you will find this very hard, especially the derivations. Send out a ship at fast speed towards a marker in space, acording to special relativity time for the ship slows down. You can see the marker, it's in general relativity time. can you still see the ship if it's in a different time? The time is relative to the frame in which you measure it... what do you mean by GR time and SR time? GR simplifies to SR for inertial frames. Is there now 2 ships one in general time and one in special time? One set of physics rules apply or the other, not both. Can special relativity be possible? Is the ship in the past or the future? Is this time travel? I hardly think so. SR can not only be possible but is an accurate description of reality, there is significant experimental evidence for it.
infinitesolid2 Posted October 29, 2009 Author Posted October 29, 2009 SR can not only be possible but is an accurate description of reality, there is significant experimental evidence for it. I still don't belive it's possible, plus theres no one in a different time to check whatever is being tested. -1
iNow Posted October 29, 2009 Posted October 29, 2009 I still don't belive it's possible Then, quite simply, what you personally believe is contradicted by the reality in which you exist.
infinitesolid2 Posted October 29, 2009 Author Posted October 29, 2009 Then, quite simply, what you personally believe is contradicted by the reality in which you exist. Theres only one time, now!, there was a past and will be a future, i don't believe any experiment can change that.
Klaynos Posted October 29, 2009 Posted October 29, 2009 I still don't belive it's possible, plus theres no one in a different time to check whatever is being tested. Put simply: The universe doesn't care what you believe. We can put people and things into other frames though and compare time measurements...
infinitesolid2 Posted October 30, 2009 Author Posted October 30, 2009 (edited) We can put people and things into other frames though and compare time measurements... Have you a link? Merged post follows: Consecutive posts mergedPut simply: The universe doesn't care what you believe. We can put people and things into other frames though and compare time measurements... Is it the case of sending a watch out a long distance and sending a signal to it and it then echoing a time signal back. then reading the time. Then send it out the same distance really fast and repeating the test? Or send time balls to mars at different speeds, when they hit mars they send back the time. Edited October 30, 2009 by infinitesolid2 Consecutive posts merged.
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